Expansion gauge



Sept. 4, 1951 s. o. swENssoN EXPANSION GAUGE Filed Deo. 21, 1948 2Sheets-Sheet l F IG.

irllll L Sept. 4, 1951 s. o. swENssoN EXPANSION GAUGE 2 Sheets-Sheet 2Filed Dec. 21, 1948 .recesses in .the members Patented Sept. 4, 1,951

`UN I TED :or FICE 2 anims.l (elfes-1,78)

This invention relates .to expansion rgauges ior taking measurements ofholes 'or' similar cavities and `has for itsprimary object to provide animproved construction which is easy `to manipu-` late and ensures a'highdegree of ,exactness I attain thisy and yother'objects bymechanismillustrated in, the accompanying drawings, in which Fig. 1. is anelevation of an expansion gauge constructed in. yaccordance with thisinvention and viewed .from the Vleft of Fig: 2,; the upper and lowerportions of'the gauge -being shown as separated from each other, andpart 'of an appertaining indicator being broken away; Fig. Zis asectional View of the gauge along the line 2 2, Fig. 3.; Fig. 3 is across-section taken on the line 3-3. Fig. 2; Fig. 4` is atop view of amodied embodiment of the invention;v Fig."v 5 is a sectional elevationthereof, the section being taken on the line 5-5, Fig. 4; and Fig. 6 visa section in part of a third embodiment of the invention.

Referring to Figs. 1 to 3, reference numerals IIJ-denote a number ofabutting members spaced from each other and disposed such asapproximately to form parts of an annular body. lThe members I havesubstantially spherical outer faces II and cylindrical .inner faces I2andare attheir inner faces soldered,V welded or'otherwise secured tocylindrical sections I3 of aresilient member, the sections I3 beinginterconnected by inwardlyprojectin'g portionsl4. The portions I4 areresilient in the circumferential direction and tend to move the sectionsI3 and members I0 radially inwardly so as to reduce the clearancesV I5between the members I0.

Centrally within the member I3, I4 there is provided a rod I6 which atits upper end is connected with a 4collar I1. The .rod I6 extends with asliding t through a guide member I8 whichby meansof a bayonet-catch I9is detachably secured to a tubular housingvZD. Near the lower end of therod I6, there is anvenlarged, `portion or .collar 2| against which restsone end of` a helical spring `22 the other lend of which `abuts against.the bottom of a recess in the guide member I8. .Between the inner'faces I2 of the abutting members `III and themembers I1 and VI8there-arefprovided slightly conical andthinwalled vcovers .23 and 24,respectively, which lat =their central. portions .are vinserted intoannular I1 and .I8 and ,at their .againstthe, faces I2 and the I3. The

outerA edgesY abuV vkupper and vlower iedges v`of the sections.

directions, but' 're `11 directi'Qn! iin-iwhicli-the collar I=1is;remotel to a .greatl distancefrom .l the .guide member-i8. z vEhecovers :23- an'd `24A maintainzztne. members .il 0, .aridi I3 in:posi-tions .suchthat .fthe .zouterpiaces .LI I .of Ithe members(A2-:IllV :are touching aan. .imaginarytscylindricalsurface indicated :bithe'glines; 4. I,j4|`in Fie; .2.41 l-I-r,1..this .costieri-rialeabutting-members II can be introduced into a hole 42, 42 having a:dia-meter .ereatelethanithe fdiametszi; the .-Cy-

41 thafhandle resiliency movmentetlm' .at

IIJ will touch imaginary cylindrical surfaces having graduallyincreasing diameters until the movement will be stopped when the faces II come into contact with the wall 42, 42 of the hole to be gauged. Sincethe movement of the rod I6 is transmitted to the pointer 38, thediameter of the hole can be read on the scale 32. In order to withdrawthe gauge from the hole, the handle 28 should be slightly depressedtoward the position indicated by full lines so as to force the abuttingmembers II) radially inwardly.

Instead of having all of the members I abut against a common cylindricalsurface it may in certain cases be desirable to gauge a hole by contactat three points only. To this end, contact members may be permanentlyand detachably secured to three of the members I0, such contact membersbeing indicated by dotted lines 43 in Fig. 3.

Turning now to the modified form of construction shown in Figs. 4 and 5,the housing 50, rod 5I, bar 52 and indicator 53 are generally designedin a similar manner, and serve the same purposes, as the correspondingparts of the embodiment described with reference to Figs. 1 to 3. Eachof the abutting members 54 is provided with two inner projections 55 and56 having vertically extending recesses or grooves which are engaged bythe edges of slotted cylindrical members 51, as will be clearly seenfrom Fig. 4 in which, for the sake of clearness, part of the upper coveris broken away and the lower cover is omitted. The cylindrical members51 consist of a suitable resilient material and tend to force themembers 54 circumferentially toward each other. In this embodiment, too,there are provided an upper conical cover 58 and a lower conical cover59 abutting against the recessed inner faces of the members 54. In thepresent instance, the apices of the cones formed by the covers aredirected inwardly against each other, whereas in the previouslydescribed embodiment they are directed from each other. In order to makethe covers as rigid and resistant as possible in the radial direction,they are formed with depressed portions BIJ, and in order to renderpossible variations of the apex angle of the cone, each cover has anumber of radial slots 6I serving the same purpose as the portions .25and 2'6 of the first embodiment.

The rod 5I is secured to the central portion of the upper cover 58 andis subject to the action of a helical spring 62 which tends to force therod upwards and thus to increase the distance between diametricallyopposed abutting members 54. The rod 5I has a collar 63 to be engaged byan arm 64 of a handle 65 pivotally mounted at 66.

The mode of operation is substantially the same as that described withreference to Figs. 1 to 3. In Fig. 5, the handle 65 is shown in itsdepressed position in which the spring 62 is compressed and the members54 can be introduced into a hole to be gauged. When the lever 65 isreleased, the spring 62 tends to make the conical covers more nearlyplane with the result that the members 54 will be forced radiallyoutwardly against the resilient action of the members 51.

In both embodiments described, the covers are preferably constructed ina manner such that in entirely unloaded conditions they are less conicalthan in their inserted positions so that the covers, too, will tend toforce the abutting mem- 4 bers outwardly against the resiliency of themembers I4 and 51.

In the embodiment illustrated in Fig. 6, the abutting members forcontacting the wall of a hole to be gauged are constituted by sections10 of a substanitally spherical hollow member 1I, the sections 10 beingspaced apart by inwardly pressed portions 12 extending along meridiansof the sphere. The member 10 is made of some resilient material, and theportions 12 tend to contract the member 16 such as to decrease thediameter d thereof. The portions 1'2 thus act in the same manner as theportions I4 shown in Figs. 2 and 3 and as the resilient members 51 shownin Figs. 4 and 5. At its bottom, the member 1I has an opening the edgesof which are tightly attached to a nipple 13 threaded into a tube 14which slidably extends into a housing f the dotted line 85.

15. Into the lower portion of the housing, there is threaded a hollowplug 16 which communicates with a Bourdon tube 11 of a pressure gauge18. Between the lower end of the tube 14 and the upper end of the plug16, a flexible bellows 19 is inserted in a liquid-tight manner. A handleor lever mounted on the housing 15 at 8| is articulated to a link 82Which is pivoted on a ring 83 inserted in a recess in the tube 14. Thehollow system, that is, the spherical member 1I and the Bourdon tube 11as well as the passages therebetween are entirely or to a considerabledegree lled with a liquid 84, such as oil.

In operation, the member 1I is introduced into the hole to be gauged.Then the lever 80 is depressed so as to force the tube 14 downwardswithin the housing 15. Due to the resultant increase in pressure of theliquid, the member 1I will be expanded until the outer faces of thesections 16 will touch the wall of the hole. The pressure of the liquidprevailing at that moment will obviously be a function of the diameterof the hole and will be indicated by the pointer of the pressure gauge18, the seal of the same being preferably graduated so as to indicatethe diameter of the hole in a convenient unit of length. It will bemanifest that the conical abutting members 23 and 24 (Fig. 2) and theconical members 58 and 59 (Fig. 5) may either directly bear against theinner faces of the abutting members I0 and 54 respectively or each mayengage a suitable member carried by the adjacent abutting member andconstitute a part thereof.

If desired, contact members may be secured to the outer faces of thesections 16, as indicated by Also in other respects, the constructionsdescribed may be modified within the scope of the appending claims.

What I claim is:

l. An expansion'gauge comprising in combination a plurality of abuttingmembers disposed circumferentially with respect to a common axis andhaving outer faces which touch an imaginary circumscribed cylindricalsurface, resilient means engaging said abutting members substantially inthe circumferential direction thereof and tend'- ing to move saidmembers radially inwardly, two substantially conical members abuttingagainst the inner faces of said abutting members, a stationary partsecured to the central portion of one of said conical members, adisplaceable rod secured to the central portion of the other one of saidconical members, said conical members being circumferentially resilient,resilient means engaging said stationary part and said rod and tendingto movesaid rod so asV to increase the apex angles of said conicalmembers whereby to move said abutting members radially outwardly againstthe action of said first-named resilient means, and means indicating theposition of said rod.

2. An expansion gauge comprising in combination a plurality of abuttingmembers disposed circumferentially with respect to a common axis andhaving outer faces which touch an imaginary circumscribedcylindricalsurface, resilient means engaging said labutting members substantiallyin the circumferential direction thereof and tending to move saidmembers radially inwardly, two sub-` stantially conical members abuttingagainst the inner faces of said abutting members, a stationary partsecured to the central portion of one of said conical members, adisplaceable rod secured to the central portion of the other oneof saidconical members, said conical members being circumferentially resilient,resilient means engaging said stationary part and said rod and tendingto move said rod so as to increase the apex angles of said conicalmembers whereby to move said abutting members radially outwardly againstthe action of said first-named resilient means, manually operable meansfor counteracting the tendency of said second-named resilient meanswhereby to decrease the apex angles of said conical members and permitsaid first-named resilient means to move'gsfaid abutting membersradially inwardly, and means indicating the position of said rod.

SVEN OLOF SWENMSSON.

i REFERENCES CITED The followingtreferences are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,557,846 Kallensee Oct. 20, 19251,631,019 Darlington May 31, 1927 1,676,248 Bryant July- 10, 19282,047,607 Zimmerman July 14, 1936 2,249,954 -Hellberg et al. July 22,1941 FOREIGN PATENTS Number Country Date y 4,190 Austria May 25, 1901138,823 Great Britain Feb. 19, 1920 OTHER REFERENCES American Machinist,June 5, 1945, page 150.

